Caption: MODEL RELEASED. Scientific research. Researcher using apparatus, known as a stirrer, to mix a chemical in a glass beaker (centre left, above her hand). Stirrers work by using magnetic force to stir the chemical inside the beaker. There is a magnetic capsule (not seen) inside the beaker, which is then magnetically rotated by the stirrer to swirl the chemical around its container. The stirrer also heats the liquid to a desired temperature, thus making the job easier for the researcher.